Occupational risks associated with chronic kidney disease of non-traditional origin (CKDnt) in Brazil: it is time to dig deeper into a neglected problem / Riscos ocupacionais associados à doença renal crônica de origem não tradicional (DRCnt) no Brasil: é hora de nos aprofundarmos em um problema negligenciado

Abstract In the past decades, an epidemic of chronic kidney disease (CKD) has been associated with environmental and occupational factors (heat stress from high workloads in hot temperatures and exposure to chemicals, such as pesticides and metals), which has been termed CKD of non-traditional origin (CKDnt). This descriptive review aims to present recent evidence about heat stress, pesticides, and metals as possible causes of CKDnt and provide an overview of the related Brazilian regulation, enforcement, and health surveillance strategies. Brazilian workers are commonly exposed to extreme heat conditions and other CKDnt risk factors, including increasing exposure to pesticides and metals. Furthermore, there is a lack of adequate regulation (and enforcement), public policies, and strategies to protect the kidney health of workers, considering the main risk factors. CKDnt is likely to be a significant cause of CKD in Brazil, since CKD's etiology is unknown in many patients and several conditions for its development are present in the country. Further epidemiological studies may be conducted to explore causal associations and estimate the impact of heat, pesticides, and metals on CKDnt in Brazil. Moreover, public policies should prioritize reducing workers´ exposure and promoting their health and safety.

Resumo Nas últimas décadas, uma epidemia de doença renal crônica (DRC) tem sido associada a fatores ambientais e ocupacionais (estresse térmico decorrente de cargas de trabalho elevadas em altas temperaturas e exposição a produtos químicos, como agrotóxicos e metais), denominada DRC de origem não tradicional (DRCnt). Esta revisão descritiva tem como objetivo apresentar evidências recentes sobre estresse térmico, agrotóxicos e metais como possíveis causas de DRCnt e fornecer uma visão geral das estratégias brasileiras de regulamentação, fiscalização e vigilância sanitária relacionadas. Os trabalhadores brasileiros são comumente expostos a condições extremas de calor e outros fatores de risco de DRCnt, incluindo o aumento da exposição a agrotóxicos e metais. Além disso, há uma falta de regulamentação e fiscalização, políticas públicas e estratégias adequadas para proteger a saúde renal dos trabalhadores em relação aos principais fatores de risco. É provável que a DRCnt seja uma causa significativa de DRC no Brasil, uma vez que a etiologia da doença é desconhecida em muitos pacientes e diversas condições para seu desenvolvimento estão presentes no país. Estudos epidemiológicos devem ser realizados para explorar associações causais e estimar o impacto do calor, dos agrotóxicos e dos metais na DRCnt no Brasil. Além disso, as políticas públicas devem priorizar a redução da exposição dos trabalhadores e a promoção de sua saúde e segurança.

Selective Detection of Paraquat in Adulterated and Complex Environmental Samples Using Raman Spectroelectrochemistry.

Growing demand for pesticides has created an environment prone to deceptive activities, where counterfeit or adulterated pesticide products infiltrate the market, often escaping rapid detection. This situation presents a significant challenge for sensor technology, crucial in identifying authentic pesticides and ensuring agricultural safety practices. Raman spectroscopy emerges as a powerful technique for detecting adulterants. Coupling the electrochemical techniques allows a more specific and selective detection and compound identification. In this study, we evaluate the efficacy of spectroelectrochemical measurements by coupling a potentiostat and Raman spectrograph to identify paraquat, a nonselective herbicide banned in several countries. Our findings demonstrate that applying -0.70 V during measurements yields highly selective Raman spectra, highlighting the primary vibrational bands of paraquat. Moreover, the selective Raman signal of paraquat was discernible in complex samples, including tap water, apple, and green cabbage, even in the presence of other pesticides such as diquat, acephate, and glyphosate. These results underscore the potential of this technique for reliable pesticide detection in diverse and complex matrices.

Repercussions of Prolonged Pesticide Use on Natural Soil Microbiome Dynamics Using Metagenomics Approach.

The residual pesticides in soil can affect the natural microbiome composition and genetic profile that drive nutrient cycling and soil fertility. In the present study, metagenomic approach was leveraged to determine modulations in nutrient cycling and microbial composition along with connected nexus of pesticide, antibiotic, and heavy metal resistance in selected crop and fallow soils having history of consistent pesticide applications. GC-MS analysis estimated residuals of chlorpyrifos, hexachlorbenzene, and dieldrin showing persistent nature of pesticides that pose selective pressure for microbial adaptation. Taxonomic profiling showed increased abundance of pesticide degrading Streptomyces, Xanthomonas, Cupriavidus, and Pseudomonas across the selected soils. Genes encoding for pesticide degrading cytochrome p450, organophosphorus hydrolase, aldehyde dehydrogenase, and oxidase were predominant and positively correlated with Bacillus, Sphingobium, and Burkholderia. Nitrogen-fixing genes (nifH, narB, and nir) were relatively less abundant in crop soils, correlating to the decrease in nitrogen-fixing bacteria (Anabaena, Pantoea, and Azotobacter). Microbial enzymes involved in carbon (pfkA, gap, pgi, and tpiA) and phosphorus cycle (gmbh and phnJ) were significantly higher in crop soils indicating extensive utilization of pesticide residuals as a nutrient source by the indigenous soil microbiota. Additionally, presence of antibiotic and heavy metal resistance genes suggested potential cross-resistance under pressure from pesticide residues. The results implied selective increase in pesticide degrading microbes with decrease in beneficial bacteria that resulted in reduced soil health and fertility. The assessment of agricultural soil microbial profile will provide a framework to develop sustainable agriculture practices to conserve soil health and fertility.

A nationwide characterization of organochlorine pesticides (OCPs) in livestock and poultry food products across China: Residual levels, origin and the associated health risks.

Organochlorine pesticides (OCPs) are still occurring in various foodstuffs after the ban on their use. However, it remains unclear concerning the contamination source of OCPs in livestock and poultry food products and associated health risks. To fill this gap, we characterized the residual levels of 19 OCPs in multiple types of meats and eggs, which were sampled across China within the same period. Dichlorodiphenyltrichloroethanes (DDTs) were dominant in eggs, with the mean levels being 0.76 and 2.03 µg/kg for chicken eggs and duck eggs, respectively. By contrast, hexachlorocyclohexanes (HCHs) were the top one OCP in beef and lamb, with its mean levels being 0.51 and 0.65 µg/kg, respectively. Hexachlorobenzene (HCB) was rather detected in the poultry products. The componential ratio analysis implicated recent inputs of several banned OCPs including technical HCH and DDT, HCB and aldrin in multiple regions, which may origin from local industrial activities or possible illegal use. Risk assessment based on the risk quotient method suggested that daily consumption of cooked meats and eggs contaminated by dieldrin may pose a carcinogenic risk in adult residents of Jiangsu province. We concluded that OCPs remain present in meats and eggs at levels of health concern regionally in China.

Feature-Agnostic Metabolomics for Determining Effective Sub-cytotoxic Doses of Common Pesticides in Human Cells.

While classical molecular biology assays can provide a measure of cellular response to chemical challenges, they rely on a single biological phenomenon to infer a broader measure of cellular metabolic response. These methods do not always afford the necessary sensitivity to answer questions of sub-cytotoxic effects, nor do they work for all cell types. Likewise, boutique assays such as cardiomyocyte beat rate may indirectly measure cellular metabolic response, but they too, are limited to measuring a specific biological phenomenon and are often limited to a single cell type. For these reasons, toxicological researchers need new approaches to determine metabolic changes across various doses in differing cell types, especially within the low-dose regime. The data collected herein demonstrate that LC-MS/MS-based untargeted metabolomics with a feature-agnostic view of the data, combined with a suite of statistical methods including an adapted environmental threshold analysis, provides a versatile, robust, and holistic approach to directly monitoring the overall cellular metabolomic response to pesticides. When employing this method in investigating two different cell types, human cardiomyocytes and neurons, this approach revealed separate sub-cytotoxic metabolomic responses at doses of 0.1 µM and 1 µM of chlorpyrifos and carbaryl. These findings suggest that this agnostic approach to untargeted metabolomics can provide a new tool for determining effective dose by metabolomics (EDm) of chemical challenges, such as pesticides, in a direct measurement of metabolomic response that is not cell type-specific or observable using traditional assays.

Effects of pesticide exposure on the expression of selected genes in normal and cancer samples: Identification of predictive biomarkers for risk assessment.

Pesticides pivotal in controlling pests, can represent a threat for human health. Regulatory agencies constantly monitor their harmful effects, regulating their use. Several studies support a positive association between long-term exposure to pesticides and chronic pathologies, such as cancer. Geno-toxicological biomonitoring has proven to be valuable to assess genetic risks associated with exposure to pesticides, representing a promising tool to improve preventive measures and identify workers at higher risk. In this study, a differential gene expression analysis of 70 candidate genes deregulated upon pesticide exposure, was performed in 10 GEO human gene expression DataSets. It was found that six genes (PMAIP1, GCLM, CD36, SQSTM1, ABCC3, NR4A2) had significant AUC predictive values. Also, CD36 was upregulated in non-transformed cell samples and healthy workers, but downregulated in cancer cells. Further validation in larger groups of workers will corroborate the importance of the identified candidates as biomarkers of exposure/effect.

In Situ Defect Engineering of Fe-MIL for Self-Enhanced Peroxidase-Like Activity.

Defect engineering is an effective strategy to enhance the enzyme-like activity of nanozymes. However, previous efforts have primarily focused on introducing defects via de novo synthesis and post-synthetic treatment, overlooking the dynamic evolution of defects during the catalytic process involving highly reactive oxygen species. Herein, a defect-engineered metal-organic framework (MOF) nanozyme with mixed linkers is reported. Over twofold peroxidase (POD)-like activity enhancement compared with unmodified nanozyme highlights the critical role of in situ defect formation in enhancing the catalytic performance of nanozyme. Experimental results reveal that highly active hydroxyl radical (•OH) generated in the catalytic process etches the 2,5-dihydroxyterephthalic acid ligands, contributing to electronic structure modulation of metal sites and enlarged pore sizes in the framework. The self-enhanced POD-like activity induced by in situ defect engineering promotes the generation of •OH, holding promise in colorimetric sensing for detecting dichlorvos. Utilizing smartphone photography for RGB value extraction, the resultant sensing platform achieves the detection for dichlorvos ranging from 5 to 300 ng mL-1 with a low detection limit of 2.06 ng mL-1. This pioneering work in creating in situ defects in MOFs to improve catalytic activity offers a novel perspective on traditional defect engineering.

Neonicotinoid Pesticides Affect Developing Neurons in Experimental Mouse Models and in Human Induced Pluripotent Stem Cell (iPSC)-Derived Neural Cultures and Organoids.

Neonicotinoids are synthetic, nicotine-derived insecticides used worldwide to protect crops and domestic animals from pest insects. The reported evidence shows that they are also able to interact with mammalian nicotine receptors (nAChRs), triggering detrimental responses in cultured neurons. Exposure to high neonicotinoid levels during the fetal period induces neurotoxicity in animal models. Considering the persistent exposure to these insecticides and the key role of nAChRs in brain development, their potential neurotoxicity on mammal central nervous system (CNS) needs further investigations. We studied here the neurodevelopmental effects of different generations of neonicotinoids on CNS cells in mouse fetal brain and primary cultures and in neuronal cells and organoids obtained from human induced pluripotent stem cells (iPSC). Neonicotinoids significantly affect neuron viability, with imidacloprid (IMI) inducing relevant alterations in synaptic protein expression, neurofilament structures, and microglia activation in vitro, and in the brain of prenatally exposed mouse fetuses. IMI induces neurotoxic effects also on developing human iPSC-derived neurons and cortical organoids. Collectively, the current findings show that neonicotinoids might induce impairment during neuro/immune-development in mouse and human CNS cells and provide new insights in the characterization of risk for the exposure to this class of pesticides.

In-situ growth of a covalent organic framework-based matrix-compatible microextraction coating for sensitive extraction of multiple pesticides.

The potential pesticide hazard to non-target organisms is a global concern. It is critical to develop the sensitive detection methods of multiple pesticides in various complex matrices. Here, benzene-1,3,5-tricarbaldehyde (BTCA) and 1,3,5-Tri (4-aminophenyl) benzene (TAPB) were employed as precursors for the in-situ growth of COFTAPB-BTCA on the surface of amino-functionalized stainless steel wire (SS) via a solvothermal method. The successful COFTAPB-BTCA bonded fiber exhibited significant enrichment capability of pyrethroids insecticides (PYs), organophosphorus (OPPs), and organochlorine (OCPs), with enrichment factors (EFs) ranging from 1133-7762, 1319-7291, and 734.1-2882, respectively. X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations indicated that various interactions contributed to its high enrichment capacity. Automated detection of PYs, OPPs, and OCPs in water, foods, and biological samples was realized by coupling this fiber with gas chromatography-mass spectrometry (GC-MS). The detection limits were as low as 0.0370-0.657 ng/L, 0.0128-0.400 ng/L, and 0.0329-0.202 ng/L for PYs, OPPs, and OCPs, respectively. In addition, the environmental risks of these samples were assessed based on the above data. This work not only provided a straightforward technique for sensitive monitoring of pesticides in complex matrices but also presented a novel approach for the in-situ controlled growth of versatile adsorbents with broad-spectrum properties.

Association between pancreatic adenocarcinoma risk and concentration of organochlorine pesticides in adipose tissue and urine: A targeted-screening analysis case-control study (PESTIPAC).

BACKGROUND: Knowledge about environmental pancreatic adenocarcinoma (PA) risk factors, including pesticide exposure, remains limited. Organochlorine (OC) accumulates in adipose tissue and can help reflect long-term exposure. PATIENTS AND METHODS: Age and body mass index (BMI) of patients with PA were matched with those undergoing a surgery for a benign disease on age and BMI (1:1). Targeted analyses screened 345 pesticides and metabolites, including 29 OC, in adipose tissue and urine samples. The primary aim was to investigate the association between organochlorine concentrations in visceral fat or urine, and PA. Adjusted conditional logistic regressions were carried out accounting for multiple testing. RESULTS: Trans-nonachlor (odds ratio [OR] = 1.325, 95% confidence interval [CI] [1.108-1.586]), cis-nonachlor (OR = 15.433, 95% CI [2.733-87.136]), Mirex (OR = 2.853, 95% CI [1.213-6.713]) and 4,4 DDE (OR = 1.019, 95% CI [1.005-1.034]) in fat and a greater number of positive samples (OR = 1.758 95% CI [1.11-2.997]) were significantly associated with higher odds of PA. In contrast, as awaited, urine samples did not yield any statistically significant associations for all tested pesticides. CONCLUSION: Some OCs were associated with higher odds of PA. The underlying mechanisms of pancreatic aggression need to be investigated to refine these findings. TRIAL REGISTRATION: Clinicaltrials.gov NCT04429490.

Empowering Agricultural Workers Through Community Health Worker-Led Pesticide Safety Workshops in Washington State.

Background: It is difficult to reach migrant or refugee agricultural workers about pesticide exposure prevention. Here, we describe a community health worker (CHW)-led pesticide exposure prevention workshop and the impact of this program among migrant and refugee workers in Washington state. Methods: A focus group of migrants and refugees participated in the development of a CHW-led Spanish language pesticide exposure prevention mobile phone app and workshop. Pre- and post-workshop surveys assessed pesticide training, knowledge, and characteristics. Results: Community health workers facilitated 28 workshops attended by 263 participants from 49 agricultural communities. Approximately 79% of participants reported no prior pesticide training. Significant improvements were observed in the proportion familiar with illnesses associated with pesticides, knowledge about pesticide definition, ability to correctly identify the content of pesticide labels, and the correct method to wash fruits and vegetables. Conclusions: Community health workers are effective in addressing the gaps in pesticide safety education and awareness among migrant and refugee communities. Further work is needed to assess how to better integrate a mobile phone app into this training and subsequent use of the knowledge.

Agricultural-Derived organochlorine pesticide residues impact on macroinvertebrate community in an Afrotropical Stream.

This study evaluated the impact of pesticide application through agricultural activities in Chanchaga River, Nigeria, using macroinvertebrate data sets obtained for six months (September 2021-February 2022). Four (4) stations, characterized by various agricultural activities, were sampled along the river. Analysis of the water samples for organochlorine pesticide residues (OCP) using Gas Chromatography-Mass Spectrometry (GC/MS) at the peak of the two seasons revealed a high concentration of eleven isomers of organochlorine, which ranged from 0.01 to 0.81 µg/L, and a mean concentration that was above international drinking water standards set by the World Health Organization, the Federal Environmental Protection Agency, and the European Union. The mean concentration of detected OCP was recorded as DDT (0.72 µg/L), Dieldrin (0.59 µg/L), Paraquat (0.54 µg/L), Aldrin (0.49 µg/L), Metribuzin (0.48 µg/L), Butachlor (0.47 µg/L), Alachlor (0.28 µg/L), Atrazine (0.23 µg/L), Phenol (0.10 µg/L), Endrin (0.09 µg/L), and Benzene (0.08 µg/L). Atrazine, alachlor, metribuzin, aldrin, phenol, and endrin showed significant differences across the two seasons (p < 0.05), while dieldrin, butachlor, paraquat, benzene, and DDT showed no significant differences across the two seasons (p > 0.05). A total of 622 macroinvertebrate individuals from 19 species in 18 families from 8 orders were collected. More individuals were collected during the dry season (58.17 %) and the wet season (41.83 %). Canonical Correspondence Analysis (CCA) ordination revealed a strong relationship between species abundance and some organochlorine pesticide residues such as DDT, endrin, metribuzin, atrazine, benzene, and dieldrin. The response of macroinvertebrates to OCP indicates that Chanchaga River is a disturbed river, and the indicator organisms (Lestes sp., Coenagrion sp., Zyxomma sp., Appasus sp., Chironomus sp., Lymnaea natalensis, and Caridina nililotica) can also be used for further biomonitoring.

Pesticides in fish from the Uruguay River and markets in Argentina and health risk assessment.

Organochlorine, organophosphate, triazole, and strobilurin pesticides were determined in fish samples. Relative standard deviations lower than 9.3% were obtained for organochlorine pesticides and 10.8% for other pesticides. Accuracy ranged from 73% to 119% for organochlorine pesticides and 80.4% to 116% for organophosphate, triazole, and strobilurin pesticides. A total of 28 pesticides were analysed and 7 of them were detected (exceeding 10 µg/kg) in some samples, with the highest concentration recorded at 68.5 µg/kg, corresponding to heptachlor epoxide A. The pesticide most frequently detected was ß HCH, found in 30 of the 100 analysed samples. Hazard Quotient values were estimated for men, women, and children. These values exceeded 1 for heptachlor epoxide in women and children, as well as for endrin in children. These findings emphasise the need for stricter controls to reduce fish contamination and mitigate health risks.

Safety evaluation of Indocalamus Iatifolius McClure leaves based on acute toxicity, harmful metals, and 9 organochlorine residue determination.

To investigate the safety of Indocalamu Iatifolius McClur leaves sold in the market, a study was conducted using Indocalamu Iatifolius McClur leaves randomly collected from an online store and a large supermarket. Acute toxicity experiments were performed on mice, and their body weight was monitored for 14 days after administration. After the observation period, blood samples were collected for biochemical analysis, and organ pathology was examined. Then, the content of copper (Cu), lead (Pb), cadmium (Cd), mercury (Hg), arsenic (As), and the residues of nine organochlorine pesticides in Indocalamu Iatifolius McClur leaves were measured according to the National Food Safety Standard (GB/T5009-2003) and the pesticide residue determination methods in the 2020 edition of the Chinese Pharmacopoeia. The results showed that the mice in the Indocalamu Iatifolius McClur leaves (online store) group experienced mortality and severe liver and lung damage. The levels of lead, cadmium, mercury, arsenic, and the nine organochlorine pesticides met the relevant standards and regulations. However, the copper content in the Indocalamu Iatifolius McClur leaves (online store) group was nearly 80 times higher than that in the supermarket group. Mice in the Indocalamu Iatifolius McClur leaves (supermarket) group remained healthy without any abnormalities, and the levels of harmful metals and organochlorine pesticides complied with the standards and regulations. The study suggests the need for regulatory policies and safety standards for the sale of Indocalamu Iatifolius McClur leaves.

Embryonic exposure to flubendiamide induces hepatotoxicity in domestic chicks by altering drug-metabolizing enzymes, antioxidant status, and liver function.

Pesticides have increased crop yield but severely impacted ecosystems and non-target organisms. Flubendiamide, a new generation pesticide, targets insect larvae but also affects non-target organisms. This study examines the effects of lowest observed effect concentration of technical grade flubendiamide (0.5 µg/µL) flubendiamide on chick liver, focusing on cytochrome P450 (CYP) enzyme expression, oxidative stress, and liver damage. Chick embryos treated with flubendiamide showed significant alterations in CYP mRNA and protein levels, indicating increased toxicant accumulation. Elevated CYP3A4, CYP1A1, CYP1A2, and CYP2C19 levels were noted, suggesting enhanced biotransformation and detoxification processes. However, increased oxidative byproducts led to oxidative stress, as evidenced by decreased glutathione (GSH) levels and elevated superoxide dismutase (SOD) and catalase activities. DCFDA staining confirmed increased hydrogen peroxide (H2O2) levels, indicating heightened reactive oxygen species (ROS). Liver function tests revealed significant increases in serum ALP, ALT, and AST levels, indicating acute liver damage. Histopathological analysis showed structural liver damage, including expanded sinusoidal spaces, impaired portal veins, and compromised hepatocyte architecture. These findings underscore flubendiamide's potential hepatotoxicity in non-target organisms, emphasizing the need for cautious pesticide use to minimize environmental impacts.

A review on toxic effects of pesticides in Zebrafish, Danio rerio and common carp, Cyprinus carpio, emphasising Atrazine herbicide.

The widespread use of pesticides has emerged as a pressing environmental concern nowadays. These chemical compounds pose a significant threat to aquatic organisms due to their toxic effects. Zebrafish and common carp are two common species used in pesticide toxicity studies. Atrazine, a widely used herbicide, is one of the most prevalent globally, detectable in nearly all surface waters. This article examines existing literature to provide a comprehensive review of the toxic effects of Atrazine on Zebrafish and common carp. The findings reveal that exposure to atrazine triggers a range of biochemical, physiological, behavioral, and genetic alterations in these fish species, even at concentrations deemed environmentally relevant. These changes could have severe consequences, including increased mortality rates, reproductive failures, and potentially leading to fish populations decline. It is, therefore, imperative to prioritize stringent regulatory measures to curb the usage of this herbicide and safeguard fish species as unintended victims of aquatic ecosystems.

Multiclass and multi-residue determination of pesticides and antibiotics in sediment from an aquacultural environment based on modified dispersive solid-phase extraction.

A quick, easy, cheap, effective, rugged, and safe method was developed for the multi-residue analysis of pesticides and antibiotics in aquaculture sediment using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The developed method is based on ultrasonic extraction with acetonitrile and phosphate buffer, salting with sodium chloride, and cleaning with dispersive solid-phase extraction adsorbent using primary secondary amine, C18, and graphitized carbon black, followed by HPLC-MS/MS detection. We optimized different extraction methods and the ratio of the cleanup adsorbents to achieve good recoveries at three spiking levels that ranged from 60.4% to 114% with a relative standard deviation below 15% (n = 6). For all analytes, except for flufenoxuron, the limits of quantification were between 1 and 5 µg/kg (dry weight). The validated method was successfully applied to real samples collected from 20 aquacultural ponds, confirming the feasibility of the proposed method. The concentrations of the target analytes in the sediments (dry weight) were in the ranges of 2.2-35.0 µg/kg for sulfonamides, 0-409.1 µg/kg for quinolones, 0-6.56 µg/kg for macrolides, and 0-4.9 µg/kg for pesticides. Moreover, the co-occurrence of pesticides and antibiotics may potentially pose a high risk to sediment-dwelling organisms in nine out of the 20 investigated locations.

Biomonitoring of 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide: A global view.

We conducted a literature review of urinary 2,4-D in populations not associated with a herbicide application. Of the 33 studies identified, the median/mean concentrations were similar for children, adults, and pregnant women regardless of geography. Individuals with highest concentrations may have had opportunities to directly contact 2,4-D outside of an application. Most studies were conducted in populations in North America and did not examine potential sources of 2,4-D, or what factors might influence higher or lower urinary 2,4-D concentrations. In the future, prioritizing the examination of 2,4-D biomonitoring in other regions and collecting information on sources and factors influencing exposures would better our understanding of 2,4-D exposures globally. In all the studies reviewed the concentrations of urinary 2,4-D observed were orders of magnitude below the US regulatory endpoints, suggesting that people are not being exposed to 2,4-D at levels high enough to result in adverse health effects.

Daily exposure to chlordecone, an organochlorine pesticide, increases cardiac fibrosis and atrial fibrillation vulnerability.

CONTEXT: Chlordecone (CLD) is a carcinogenic organochlorine pesticide. CLD was shown to disturb the activity of cardiac Na+-K+-ATPase and Ca2+-Mg2+-ATPase. Conditions affecting these transmembrane pumps are often associated with cardiac arrhythmias (CA). However, little is known about the role of CLD on atrial fibrillation (AF) incidence, the most common type of CA. HYPOTHESES: 1) Daily ingestion of CLD induces arrhythmogenic cardiac remodeling. 2) A phase of CLD withdrawal can reduce CLD-induced AF susceptibility. METHODS: Adult male Wistar rats (250 g-275 g) ingested daily-doses of CLD (0 µg/L, 0.1 µg/L, or 1 µg/L) diluted in their quotidian water for 4 weeks. From day (D)29 to D56, all rats received CLD-free water. Vulnerability to AF and cardiac function were evaluated at D28 and D56 by electrophysiological study, echocardiography, and optical-mapping. Levels of genes and proteins related to inflammation, fibrosis, and senescence were quantified by qPCR and immunoassays. RESULTS: Twenty-eight days of CLD exposure were associated with significantly increased AF vulnerability compared to CLD-free rats. Contamination with 1 µg/L CLD significantly reduced atrial conduction velocity (ERP, APD). CLD-weaning normalized food consumption and weight intake. However, after the CLD-withdrawal period of 28 days, AF inducibility, atrial inflammation (IL6, IL1ß), and atrial fibrosis (Masson's trichrome staining) remained significantly higher in rats exposed to 1 µg/L CLD compared to 0 µg/L. CONCLUSIONS: Prolonged CLD ingestion provokes atrial conduction slowing and increased risk of AF. Although CLD-weaning, some persistent damages occurred in the atrium like atrial fibrosis and atrial senescence signals, which are accompanied by atrial inflammation and arrhythmogenicity.

Identification of key anthropogenic and land use factors and ecological risk assessment of dissolved polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) in an urbanized estuary in China.

This study investigated dissolved PAHs and OCPs in Quanzhou Bay estuaries, assessed their ecological risk, and examined anthropogenic impacts on contaminant distribution. Results showed that dissolved ∑24PAH concentrations ranged from 117 to 709 ng/L (mean: 358 ng/L), with dominance of 2-ring PAHs (Naphthalene, 1-Methylnaphthalene, and 2-Methylnaphthalene). Dissolved DDT levels ranged from 0.06 to 0.49 ng/L (mean: 0.28 ng/L), while HCBz concentrations varied from 0.02 to 0.44 ng/L (mean: 0.20 ng/L). PAHs were higher in the north due to urbanization and transport, while OCPs showed higher levels in the south due to historical agricultural use. Rural areas, water bodies, and wetlands significantly influenced the behavior of PAHs according to Spearman correlation and lasso regression analyses. Quanzhou Bay was categorized as a low to medium risk area based on dispersion simulation and ecological risk assessment, highlighting implications for future sustainable development and policy planning. CAPSULE: The coupled relationship between human activities and the distribution of dissolved PAHs and OCPs in urbanized estuaries was explored using statistical methods and GIS technology, providing valuable insights into environmental processes and pollutant control policies.